IN74AC138 1-OF-8 DECODER/DEMULTIPLEXER High-Speed Silicon-Gate CMOS • • • • • The IN74AC138 is identical in pinout to the LS/ALS138, HC/HCT138. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LS/ALS outputs. The IN74AC138 decodes a three-bit Address to one-of-eight active-low outputs. This device features three Chip Select inputs, two active-low and one active-high to facilitate the demultiplexing, cascading, and chip-selecting functions. The demultiplexing function is accomplished by using the Address inputs to select the desired device output; one of the Chip Selects is used as a data input while the other Chip Selects are held in their active states. Outputs Directly Interface to CMOS, NMOS, and TTL Operating Voltage Range: 2.0 to 6.0 V Low Input Current: 1.0 µA; 0.1 µA @ 25°C High Noise Immunity Characteristic of CMOS Devices Outputs Source/Sink 24 mA ORDERING INFORMATION IN74AC138N Plastic IN74AC138D SOIC TA = -40° to 85° C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE PIN 16 =VCC PIN 8 = GND Inputs CS1 CS2 CS3 A2 A1 A0 X X H X X X X H X X X X L X X X X X H L L L L L H L L L L H H L L L H L H L L L H H H L L H L L H L L H L H H L L H H L H L L H H H Outputs Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 H H H H H H H H H H H H H H H H H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H = high level (steady state) L = low level (steady state) X = don’t care 1 IN74AC138 MAXIMUM RATINGS* Symbol Parameter Value Unit VCC DC Supply Voltage (Referenced to GND) -0.5 to +7.0 V VIN DC Input Voltage (Referenced to GND) -0.5 to VCC +0.5 V VOUT DC Output Voltage (Referenced to GND) -0.5 to VCC +0.5 V IIN DC Input Current, per Pin mA ±20 IOUT DC Output Sink/Source Current, per Pin mA ±50 ICC DC Supply Current, VCC and GND Pins mA ±50 PD Power Dissipation in Still Air, Plastic DIP+ 750 mW SOIC Package+ 500 Tstg Storage Temperature -65 to +150 °C 260 TL Lead Temperature, 1 mm from Case for 10 °C Seconds (Plastic DIP or SOIC Package) * Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions. +Derating - Plastic DIP: - 10 mW/°C from 65° to 125°C SOIC Package: : - 7 mW/°C from 65° to 125°C RECOMMENDED OPERATING CONDITIONS Symbol Parameter VCC DC Supply Voltage (Referenced to GND) VIN, VOUT DC Input Voltage, Output Voltage (Referenced to GND) TJ Junction Temperature (PDIP) TA Operating Temperature, All Package Types IOH Output Current - High IOL Output Current - Low t r, tf Input Rise and Fall Time * VCC =3.0 V VCC =4.5 V (except Schmitt Inputs) VCC =5.5 V * VIN from 30% to 70% VCC Min 2.0 0 -40 0 0 0 Max 6.0 VCC Unit V V 140 +85 -24 24 150 40 25 °C °C mA mA ns/V This device contains protection circuitry to guard against damage due to high static voltages or electric fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this high-impedance circuit. For proper operation, VIN and VOUT should be constrained to the range GND≤(VIN or VOUT)≤VCC. Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or VCC). Unused outputs must be left open. 2 IN74AC138 DC ELECTRICAL CHARACTERISTICS(Voltages Referenced to GND) Guaranteed VCC Limits Symbol Parameter Test Conditions V 25 °C -40°C to 85°C 2.1 2.1 VIH Minimum High- VOUT=0.1 V or VCC-0.1 V 3.0 3.15 3.15 Level Input 4.5 3.85 3.85 Voltage 5.5 0.9 0.9 VIL Maximum Low - VOUT=0.1 V or VCC-0.1 V 3.0 1.35 1.35 Level Input 4.5 1.65 1.65 Voltage 5.5 2.9 2.9 VOH Minimum High- IOUT ≤ -50 µA 3.0 4.4 4.4 Level Output 4.5 5.4 5.4 Voltage 5.5 * VIN=VIH or VIL 2.46 2.56 IOH=-12 mA 3.0 3.76 3.86 IOH=-24 mA 4.5 4.76 4.86 5.5 IOH=-24 mA 0.1 0.1 VOL Maximum Low- IOUT ≤ 50 µA 3.0 0.1 0.1 Level Output 4.5 0.1 0.1 Voltage 5.5 * VIN= VIH or VIL 0.44 0.36 IOL=12 mA 3.0 0.44 0.36 IOL=24 mA 4.5 0.44 0.36 5.5 IOL=24 mA IIN Maximum Input VIN=VCC or GND 5.5 ±0.1 ±1.0 Leakage Current VOLD=1.65 V Max IOLD +Minimum 5.5 75 Dynamic Output Current VOHD=3.85 V Min IOHD +Minimum 5.5 -75 Dynamic Output Current VIN=VCC or GND ICC Maximum 5.5 8.0 80 Quiescent Supply Current (per Package) * All outputs loaded; thresholds on input associated with output under test. +Maximum test duration 2.0 ms, one output loaded at a time. Note: IIN and ICC @ 3.0 V are guaranteed to be less than or equal to the respective VCC 3 Unit V V V V µA mA mA µA limit @ 5.5 V IN74AC138 AC ELECTRICAL CHARACTERISTICS(CL=50pF,Input tr=tf=3.0 ns) VCC Guaranteed Limits * Symbol tPLH tPHL tPLH tPHL tPLH tPHL CIN Parameter V Propagation Delay, Input A to Output Y (Figure 1) Propagation Delay, Input A to Output Y (Figure 1) Propagation Delay, CS2 or CS3 to Output Y (Figure 3) Propagation Delay, CS2 or CS3 to Output Y (Figure 3) Propagation Delay, CS1 to Output Y (Figure 2) Propagation Delay, CS1 to Output Y (Figure 2) Maximum Input Capacitance 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 3.3 5.0 5.0 25 °C Min 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Max 13.0 9.5 12.5 9.0 15.0 11.0 13.5 9.5 15.5 11.0 13.0 8.0 4.5 -40°C to 85°C Min Max 1.5 15.0 1.5 10.5 1.5 14.0 1.5 10.5 1.5 16.0 1.5 12.0 1.5 15.0 1.5 10.5 1.5 16.5 1.5 12.5 1.5 14.0 1.0 9.5 4.5 Typical @25°C,VCC=5.0 V 60 CPD Power Dissipation Capacitance * Voltage Range 3.3 V is 3.3 V ±0.3 V Voltage Range 5.0 V is 5.0 V ±0.5 V Figure 1. Switching Waveforms Figure 2. Switching Waveforms Figure 3. Switching Waveforms 4 Unit ns ns ns ns ns ns pF pF IN74AC138 EXPANDED LOGIC DIAGRAM 5